Scrotum

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Image:Male anatomy.png

In some male mammals, the scrotum is an external bag of skin and muscle containing the testicles. It is an extension of the abdomen, and is located between the penis and anus. The female homologue during fetal development is the labia majora.

The function of the scrotum appears to be to keep the testicles at a temperature slightly lower than that of the rest of the body. For the human, a temperature around 34.4 degrees Celsius (94 degrees Fahrenheit) appears to be ideal; 36.7 degrees Celsius (98 degree Fahrenheit) may be damaging to sperm count. The temperature is controlled by making the scrotum tighter or looser, hence moving the testicles closer to the abdomen when it is cold, and away when hot, through the cremasteric reflex, the gradual tightening and loosening of the cremaster muscle in the abdomen and the dartos fascia (muscular tissue under the skin) in the scrotum.

Although the ideal temperature for sperm growth varies between species, it usually appears, in warm-blooded species, to be a bit cooler than internal body temperature, necessitating the scrotum. Since this leaves them vulnerable in many species, there is some debate on the evolutionary advantage of such a system. One theory is that making sperm highly sensitive to elevated body temperature prevents impregnation of females who are ill.

In humans and some other mammals the base of the scrotum becomes covered with pubic hair at puberty.

The area below the scrotum, is the perineum.

Health issues

Image:Scrotum.jpg

A common problem of the scrotum is the development of masses. Common scrotal masses include

Other conditions include:

  • contact dermatitis: may cause redness, swelling, and itching of the entire scrotum. Can result from soaps, solvents, detergents, and natural irritants such as poison ivy.
  • inguinal hernia
  • yeast infection
  • swelling resulting from conditions external to the scrotum, including:

See also

Reproductive system - edit
Female - Cervix | Clitoris | Clitoral hood | Fallopian tubes | Bartholin's glands | G-spot | Hymen | Labium | Mammary glands | Ovaries | Skene's glands | Urethra | Uterus | Vagina | Vulva
Male - Urethra | Testes | Scrotum | Spermatic cord | Epididymis | Seminiferous tubules | Sertoli cell | Rete testis | Efferent ducts | Vas deferens | Seminal vesicles | Ejaculatory duct | Penis | Corpus cavernosum | Glans penis | Fundiform ligament | Foreskin | Frenulum | Prostate | Bulbourethral glands 

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